if选择结构 

 1 package com.pingfan.struct;
 2 
 3 import java.util.Scanner;
 4 
 5 public class IfDemo1 {
 6     public static void main(String[] args) {
 7         Scanner scanner = new Scanner(System.in);
 8         System.out.println("请输入内容：");
 9         String s =scanner.nextLine();
10 
11         //equals：判断字符串是否相等
12         if(s.equals("Hello")){
13             System.out.println(s);
14         }
15         System.out.println("End");
16         scanner.close();
17     }
18 }
 1 package com.pingfan.struct;
 2 
 3 import java.util.Scanner;
 4 
 5 public class IfDemo2 {
 6     public static void main(String[] args) {
 7         //考试分数大于60就是及格，小于60分就是不及格。
 8         Scanner scanner = new Scanner(System.in);
 9         System.out.println("请输入成绩");
10         int score = scanner.nextInt();
11         if(score>60){
12             System.out.println("及格");
13         }else{
14             System.out.println("不及格");
15         }
16         scanner.close();
17     }
18 }
 1 package com.pingfan.struct;
 2 
 3 import java.util.Scanner;
 4 
 5 public class IfDemo3 {
 6     public static void main(String[] args) {
 7         //考试分数大于60就是及格，小于60分就是不及格。
 8         Scanner scanner = new Scanner(System.in);
 9         System.out.println("请输入成绩");
10         int score = scanner.nextInt();
11 
12         if(score==100){
13             System.out.println("恭喜满分");
14         }else if(score<100 && score>=90){
15             System.out.println("A级");
16         }else if(score<90 && score>=80){
17             System.out.println("B级");
18         }else if(score<80 && score>=70){
19             System.out.println("C级");
20         }else if(score<70 && score>=60){
21             System.out.println("D级");
22         }else if(score<60 && score>=0){
23             System.out.println("不及格");
24         }
25         else {
26             System.out.println("成绩不合法");
27         }
28         scanner.close();
29     }
30 }

 

posted @ 2021-03-21 20:18  HeartlessHero  阅读(31)  评论(0)    收藏  举报